Source: lib/media/segment_reference.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.media.InitSegmentReference');
  8. goog.provide('shaka.media.SegmentReference');
  10. goog.require('goog.asserts');
  11. goog.require('shaka.log');
  12. goog.require('shaka.util.ArrayUtils');
  13. goog.require('shaka.util.BufferUtils');
  16. /**
  17.  * Creates an InitSegmentReference, which provides the location to an
  18.  * initialization segment.
  19.  *
  20.  * @export
  21.  */
  22. shaka.media.InitSegmentReference = class {
  23.   /**
  24.    * @param {function():!Array.<string>} uris A function that creates the URIs
  25.    *   of the resource containing the segment.
  26.    * @param {number} startByte The offset from the start of the resource to the
  27.    *   start of the segment.
  28.    * @param {?number} endByte The offset from the start of the resource
  29.    *   to the end of the segment, inclusive.  A value of null indicates that the
  30.    *   segment extends to the end of the resource.
  31.    * @param {null|shaka.extern.MediaQualityInfo=} mediaQuality Information about
  32.    *   the quality of the media associated with this init segment.
  33.    * @param {(null|number)=} timescale
  34.    * @param {(null|BufferSource)=} segmentData
  35.    * @param {?shaka.extern.aes128Key=} aes128Key
  36.    *  The segment's AES-128-CBC full segment encryption key and iv.
  37.    */
  38.   constructor(uris, startByte, endByte, mediaQuality = null, timescale = null,
  39.       segmentData = null, aes128Key = null) {
  40.     /** @type {function():!Array.<string>} */
  41.     this.getUris = uris;
  43.     /** @const {number} */
  44.     this.startByte = startByte;
  46.     /** @const {?number} */
  47.     this.endByte = endByte;
  49.     /** @const {shaka.extern.MediaQualityInfo|null} */
  50.     this.mediaQuality = mediaQuality;
  52.     /** @type {number|null} */
  53.     this.timescale = timescale;
  55.     /** @type {BufferSource|null} */
  56.     this.segmentData = segmentData;
  58.     /** @type {?shaka.extern.aes128Key} */
  59.     this.aes128Key = aes128Key;
  61.     /** @type {?string} */
  62.     this.codecs = null;
  64.     /** @type {?string} */
  65.     this.mimeType = null;
  66.   }
  68.   /**
  69.    * Returns the offset from the start of the resource to the
  70.    * start of the segment.
  71.    *
  72.    * @return {number}
  73.    * @export
  74.    */
  75.   getStartByte() {
  76.     return this.startByte;
  77.   }
  79.   /**
  80.    * Returns the offset from the start of the resource to the end of the
  81.    * segment, inclusive.  A value of null indicates that the segment extends
  82.    * to the end of the resource.
  83.    *
  84.    * @return {?number}
  85.    * @export
  86.    */
  87.   getEndByte() {
  88.     return this.endByte;
  89.   }
  91.   /**
  92.    * Returns the size of the init segment.
  93.    * @return {?number}
  94.    */
  95.   getSize() {
  96.     if (this.endByte) {
  97.       return this.endByte - this.startByte;
  98.     } else {
  99.       return null;
  100.     }
  101.   }
  103.   /**
  104.    * Returns media quality information for the segments associated with
  105.    * this init segment.
  106.    *
  107.    * @return {?shaka.extern.MediaQualityInfo}
  108.    */
  109.   getMediaQuality() {
  110.     return this.mediaQuality;
  111.   }
  113.   /**
  114.    * Return the segment data.
  115.    *
  116.    * @return {?BufferSource}
  117.    */
  118.   getSegmentData() {
  119.     return this.segmentData;
  120.   }
  123.   /**
  124.    * Check if two initSegmentReference have all the same values.
  125.    * @param {?shaka.media.InitSegmentReference} reference1
  126.    * @param {?shaka.media.InitSegmentReference} reference2
  127.    * @return {boolean}
  128.    */
  129.   static equal(reference1, reference2) {
  130.     const ArrayUtils = shaka.util.ArrayUtils;
  131.     const BufferUtils = shaka.util.BufferUtils;
  133.     if (reference1 === reference2) {
  134.       return true;
  135.     } else if (!reference1 || !reference2) {
  136.       return reference1 == reference2;
  137.     } else {
  138.       return reference1.getStartByte() == reference2.getStartByte() &&
  139.           reference1.getEndByte() == reference2.getEndByte() &&
  140.           ArrayUtils.equal(
  141.               reference1.getUris().sort(), reference2.getUris().sort()) &&
  142.           BufferUtils.equal(reference1.getSegmentData(),
  143.               reference2.getSegmentData());
  144.     }
  145.   }
  146. };
  149. /**
  150.  * SegmentReference provides the start time, end time, and location to a media
  151.  * segment.
  152.  *
  153.  * @export
  154.  */
  155. shaka.media.SegmentReference = class {
  156.   /**
  157.    * @param {number} startTime The segment's start time in seconds.
  158.    * @param {number} endTime The segment's end time in seconds.  The segment
  159.    *   ends the instant before this time, so |endTime| must be strictly greater
  160.    *   than |startTime|.
  161.    * @param {function():!Array.<string>} uris
  162.    *   A function that creates the URIs of the resource containing the segment.
  163.    * @param {number} startByte The offset from the start of the resource to the
  164.    *   start of the segment.
  165.    * @param {?number} endByte The offset from the start of the resource to the
  166.    *   end of the segment, inclusive.  A value of null indicates that the
  167.    *   segment extends to the end of the resource.
  168.    * @param {shaka.media.InitSegmentReference} initSegmentReference
  169.    *   The segment's initialization segment metadata, or null if the segments
  170.    *   are self-initializing.
  171.    * @param {number} timestampOffset
  172.    *   The amount of time, in seconds, that must be added to the segment's
  173.    *   internal timestamps to align it to the presentation timeline.
  174.    *   <br>
  175.    *   For DASH, this value should equal the Period start time minus the first
  176.    *   presentation timestamp of the first frame/sample in the Period.  For
  177.    *   example, for MP4 based streams, this value should equal Period start
  178.    *   minus the first segment's tfdt box's 'baseMediaDecodeTime' field (after
  179.    *   it has been converted to seconds).
  180.    *   <br>
  181.    *   For HLS, this value should be the start time of the most recent
  182.    *   discontinuity, or 0 if there is no preceding discontinuity. Only used
  183.    *   in segments mode.
  184.    * @param {number} appendWindowStart
  185.    *   The start of the append window for this reference, relative to the
  186.    *   presentation.  Any content from before this time will be removed by
  187.    *   MediaSource.
  188.    * @param {number} appendWindowEnd
  189.    *   The end of the append window for this reference, relative to the
  190.    *   presentation.  Any content from after this time will be removed by
  191.    *   MediaSource.
  192.    * @param {!Array.<!shaka.media.SegmentReference>=} partialReferences
  193.    *   A list of SegmentReferences for the partial segments.
  194.    * @param {?string=} tilesLayout
  195.    *   The value is a grid-item-dimension consisting of two positive decimal
  196.    *   integers in the format: column-x-row ('4x3'). It describes the
  197.    *   arrangement of Images in a Grid. The minimum valid LAYOUT is '1x1'.
  198.    * @param {?number=} tileDuration
  199.    *  The explicit duration of an individual tile within the tiles grid.
  200.    *  If not provided, the duration should be automatically calculated based on
  201.    *  the duration of the reference.
  202.    * @param {?number=} syncTime
  203.    *  A time value, expressed in seconds since 1970, which is used to
  204.    *  synchronize between streams.  Both produced and consumed by the HLS
  205.    *  parser.  Other components should not need this value.
  206.    * @param {shaka.media.SegmentReference.Status=} status
  207.    *  The segment status is used to indicate that a segment does not exist or is
  208.    *  not available.
  209.    * @param {?shaka.extern.aes128Key=} aes128Key
  210.    *  The segment's AES-128-CBC full segment encryption key and iv.
  211.    * @param {boolean=} allPartialSegments
  212.    *  Indicate if the segment has all partial segments
  213.    */
  214.   constructor(
  215.       startTime, endTime, uris, startByte, endByte, initSegmentReference,
  216.       timestampOffset, appendWindowStart, appendWindowEnd,
  217.       partialReferences = [], tilesLayout = '', tileDuration = null,
  218.       syncTime = null, status = shaka.media.SegmentReference.Status.AVAILABLE,
  219.       aes128Key = null, allPartialSegments = false) {
  220.     // A preload hinted Partial Segment has the same startTime and endTime.
  221.     goog.asserts.assert(startTime <= endTime,
  222.         'startTime must be less than or equal to endTime');
  223.     goog.asserts.assert((endByte == null) || (startByte < endByte),
  224.         'startByte must be < endByte');
  226.     /** @type {number} */
  227.     this.startTime = startTime;
  229.     /** @type {number} */
  230.     this.endTime = endTime;
  232.     /**
  233.      * The "true" end time of the segment, without considering the period end
  234.      * time.  This is necessary for thumbnail segments, where timing requires us
  235.      * to know the original segment duration as described in the manifest.
  236.      * @type {number}
  237.      */
  238.     this.trueEndTime = endTime;
  240.     /** @type {function():!Array.<string>} */
  241.     this.getUrisInner = uris;
  243.     /** @const {number} */
  244.     this.startByte = startByte;
  246.     /** @const {?number} */
  247.     this.endByte = endByte;
  249.     /** @type {shaka.media.InitSegmentReference} */
  250.     this.initSegmentReference = initSegmentReference;
  252.     /** @type {number} */
  253.     this.timestampOffset = timestampOffset;
  255.     /** @type {number} */
  256.     this.appendWindowStart = appendWindowStart;
  258.     /** @type {number} */
  259.     this.appendWindowEnd = appendWindowEnd;
  261.     /** @type {!Array.<!shaka.media.SegmentReference>} */
  262.     this.partialReferences = partialReferences;
  264.     /** @type {?string} */
  265.     this.tilesLayout = tilesLayout;
  267.     /** @type {?number} */
  268.     this.tileDuration = tileDuration;
  270.     /**
  271.      * A time value, expressed in seconds since 1970, which is used to
  272.      * synchronize between streams.  Both produced and consumed by the HLS
  273.      * parser.  Other components should not need this value.
  274.      *
  275.      * @type {?number}
  276.      */
  277.     this.syncTime = syncTime;
  279.     /** @type {shaka.media.SegmentReference.Status} */
  280.     this.status = status;
  282.     /** @type {boolean} */
  283.     this.preload = false;
  285.     /** @type {boolean} */
  286.     this.independent = true;
  288.     /** @type {boolean} */
  289.     this.byterangeOptimization = false;
  291.     /** @type {?shaka.extern.aes128Key} */
  292.     this.aes128Key = aes128Key;
  294.     /** @type {?shaka.media.SegmentReference.ThumbnailSprite} */
  295.     this.thumbnailSprite = null;
  297.     /** @type {number} */
  298.     this.discontinuitySequence = 0;
  300.     /** @type {boolean} */
  301.     this.allPartialSegments = allPartialSegments;
  303.     /** @type {boolean} */
  304.     this.partial = false;
  306.     /** @type {boolean} */
  307.     this.lastPartial = false;
  309.     for (const partial of this.partialReferences) {
  310.       partial.markAsPartial();
  311.     }
  312.     if (this.allPartialSegments && this.partialReferences.length) {
  313.       const lastPartial =
  314.           this.partialReferences[this.partialReferences.length - 1];
  315.       lastPartial.markAsLastPartial();
  316.     }
  318.     /** @type {?string} */
  319.     this.codecs = null;
  321.     /** @type {?string} */
  322.     this.mimeType = null;
  323.   }
  325.   /**
  326.    * Creates and returns the URIs of the resource containing the segment.
  327.    *
  328.    * @return {!Array.<string>}
  329.    * @export
  330.    */
  331.   getUris() {
  332.     return this.getUrisInner();
  333.   }
  335.   /**
  336.    * Returns the segment's start time in seconds.
  337.    *
  338.    * @return {number}
  339.    * @export
  340.    */
  341.   getStartTime() {
  342.     return this.startTime;
  343.   }
  345.   /**
  346.    * Returns the segment's end time in seconds.
  347.    *
  348.    * @return {number}
  349.    * @export
  350.    */
  351.   getEndTime() {
  352.     return this.endTime;
  353.   }
  355.   /**
  356.    * Returns the offset from the start of the resource to the
  357.    * start of the segment.
  358.    *
  359.    * @return {number}
  360.    * @export
  361.    */
  362.   getStartByte() {
  363.     return this.startByte;
  364.   }
  366.   /**
  367.    * Returns the offset from the start of the resource to the end of the
  368.    * segment, inclusive.  A value of null indicates that the segment extends to
  369.    * the end of the resource.
  370.    *
  371.    * @return {?number}
  372.    * @export
  373.    */
  374.   getEndByte() {
  375.     return this.endByte;
  376.   }
  378.   /**
  379.    * Returns the size of the segment.
  380.    * @return {?number}
  381.    */
  382.   getSize() {
  383.     if (this.endByte) {
  384.       return this.endByte - this.startByte;
  385.     } else {
  386.       return null;
  387.     }
  388.   }
  390.   /**
  391.    * Returns true if it contains partial SegmentReferences.
  392.    * @return {boolean}
  393.    */
  394.   hasPartialSegments() {
  395.     return this.partialReferences.length > 0;
  396.   }
  398.   /**
  399.    * Returns true if it contains all partial SegmentReferences.
  400.    * @return {boolean}
  401.    */
  402.   hasAllPartialSegments() {
  403.     return this.allPartialSegments;
  404.   }
  406.   /**
  407.    * Returns the segment's tiles layout. Only defined in image segments.
  408.    *
  409.    * @return {?string}
  410.    * @export
  411.    */
  412.   getTilesLayout() {
  413.     return this.tilesLayout;
  414.   }
  416.   /**
  417.    * Returns the segment's explicit tile duration.
  418.    * Only defined in image segments.
  419.    *
  420.    * @return {?number}
  421.    * @export
  422.    */
  423.   getTileDuration() {
  424.     return this.tileDuration;
  425.   }
  427.   /**
  428.    * Returns the segment's status.
  429.    *
  430.    * @return {shaka.media.SegmentReference.Status}
  431.    * @export
  432.    */
  433.   getStatus() {
  434.     return this.status;
  435.   }
  437.   /**
  438.    * Mark the reference as unavailable.
  439.    *
  440.    * @export
  441.    */
  442.   markAsUnavailable() {
  443.     this.status = shaka.media.SegmentReference.Status.UNAVAILABLE;
  444.   }
  446.   /**
  447.    * Mark the reference as preload.
  448.    *
  449.    * @export
  450.    */
  451.   markAsPreload() {
  452.     this.preload = true;
  453.   }
  455.   /**
  456.    * Returns true if the segment is preloaded.
  457.    *
  458.    * @return {boolean}
  459.    * @export
  460.    */
  461.   isPreload() {
  462.     return this.preload;
  463.   }
  465.   /**
  466.    * Mark the reference as non-independent.
  467.    *
  468.    * @export
  469.    */
  470.   markAsNonIndependent() {
  471.     this.independent = false;
  472.   }
  474.   /**
  475.    * Returns true if the segment is independent.
  476.    *
  477.    * @return {boolean}
  478.    * @export
  479.    */
  480.   isIndependent() {
  481.     return this.independent;
  482.   }
  484.   /**
  485.    * Mark the reference as partial.
  486.    *
  487.    * @export
  488.    */
  489.   markAsPartial() {
  490.     this.partial = true;
  491.   }
  493.   /**
  494.    * Returns true if the segment is partial.
  495.    *
  496.    * @return {boolean}
  497.    * @export
  498.    */
  499.   isPartial() {
  500.     return this.partial;
  501.   }
  503.   /**
  504.    * Mark the reference as being the last part of the full segment
  505.    *
  506.    * @export
  507.    */
  508.   markAsLastPartial() {
  509.     this.lastPartial = true;
  510.   }
  512.   /**
  513.    * Returns true if reference as being the last part of the full segment.
  514.    *
  515.    * @return {boolean}
  516.    * @export
  517.    */
  518.   isLastPartial() {
  519.     return this.lastPartial;
  520.   }
  522.   /**
  523.    * Mark the reference as byterange optimization.
  524.    *
  525.    * The "byterange optimization" means that it is playable using MP4 low
  526.    * latency streaming with chunked data.
  527.    *
  528.    * @export
  529.    */
  530.   markAsByterangeOptimization() {
  531.     this.byterangeOptimization = true;
  532.   }
  534.   /**
  535.    * Returns true if the segment has a byterange optimization.
  536.    *
  537.    * @return {boolean}
  538.    * @export
  539.    */
  540.   hasByterangeOptimization() {
  541.     return this.byterangeOptimization;
  542.   }
  544.   /**
  545.    * Set the segment's thumbnail sprite.
  546.    *
  547.    * @param {shaka.media.SegmentReference.ThumbnailSprite} thumbnailSprite
  548.    * @export
  549.    */
  550.   setThumbnailSprite(thumbnailSprite) {
  551.     this.thumbnailSprite = thumbnailSprite;
  552.   }
  554.   /**
  555.    * Returns the segment's thumbnail sprite.
  556.    *
  557.    * @return {?shaka.media.SegmentReference.ThumbnailSprite}
  558.    * @export
  559.    */
  560.   getThumbnailSprite() {
  561.     return this.thumbnailSprite;
  562.   }
  564.   /**
  565.    * Offset the segment reference by a fixed amount.
  566.    *
  567.    * @param {number} offset The amount to add to the segment's start and end
  568.    *   times.
  569.    * @export
  570.    */
  571.   offset(offset) {
  572.     this.startTime += offset;
  573.     this.endTime += offset;
  574.     this.trueEndTime += offset;
  576.     for (const partial of this.partialReferences) {
  577.       partial.startTime += offset;
  578.       partial.endTime += offset;
  579.       partial.trueEndTime += offset;
  580.     }
  581.   }
  583.   /**
  584.    * Sync this segment against a particular sync time that will serve as "0" in
  585.    * the presentation timeline.
  586.    *
  587.    * @param {number} lowestSyncTime
  588.    * @export
  589.    */
  590.   syncAgainst(lowestSyncTime) {
  591.     if (this.syncTime == null) {
  592.       shaka.log.alwaysError('Sync attempted without sync time!');
  593.       return;
  594.     }
  595.     const desiredStart = this.syncTime - lowestSyncTime;
  596.     const offset = desiredStart - this.startTime;
  597.     if (Math.abs(offset) >= 0.001) {
  598.       this.offset(offset);
  599.     }
  600.   }
  602.   /**
  603.    * Updates the init segment reference and propagates the update to all partial
  604.    * references.
  605.    * @param {shaka.media.InitSegmentReference} initSegmentReference
  606.    */
  607.   updateInitSegmentReference(initSegmentReference) {
  608.     this.initSegmentReference = initSegmentReference;
  609.     for (const partialReference of this.partialReferences) {
  610.       partialReference.updateInitSegmentReference(initSegmentReference);
  611.     }
  612.   }
  613. };
  616. /**
  617.  * Rather than using booleans to communicate what the state of the reference,
  618.  * we have this enum.
  619.  *
  620.  * @enum {number}
  621.  * @export
  622.  */
  623. shaka.media.SegmentReference.Status = {
  624.   AVAILABLE: 0,
  625.   UNAVAILABLE: 1,
  626.   MISSING: 2,
  627. };
  630. /**
  631.  * A convenient typedef for when either type of reference is acceptable.
  632.  *
  633.  * @typedef {shaka.media.InitSegmentReference|shaka.media.SegmentReference}
  634.  */
  635. shaka.media.AnySegmentReference;
  638. /**
  639.  * @typedef {{
  640.  *   height: number,
  641.  *   positionX: number,
  642.  *   positionY: number,
  643.  *   width: number
  644.  * }}
  645.  *
  646.  * @property {number} height
  647.  *    The thumbnail height in px.
  648.  * @property {number} positionX
  649.  *    The thumbnail left position in px.
  650.  * @property {number} positionY
  651.  *    The thumbnail top position in px.
  652.  * @property {number} width
  653.  *    The thumbnail width in px.
  654.  * @export
  655.  */
  656. shaka.media.SegmentReference.ThumbnailSprite;